1. Field of the Invention
The present invention relates to a digital broadcast receiver and a method for receiving and outputting digital broadcasts, and more particularly, relates to a receiver and a method for outputting appropriate signals (sound, image) during a waiting time in changing of channels, or the like.
2. Description of the Related Art
Digital broadcasting is expected to provide various advantages such as higher signal quality and more channels compared with conventional analog broadcasts. In the present specification, digital broadcasting for mobile stations will be described. However, the present invention is not limited to the broadcast for mobile stations.
In a digital broadcast, processes such as error correction and data decoding are performed on received signals, and then the received signals are output to users. Accordingly, the received signals cannot be output immediately after a receiver is turned on. In addition, the received signals cannot be output immediately after changing-over of receiving channels. As used in the present specification, the period from the switching-on of a power source or the changing of channels until outputting received signals is called a xe2x80x9cwaiting time.xe2x80x9d
As described above, a conventional receiver cannot output the receiving signal until the waiting time has elapsed. Accordingly, for example, for digital radio, resulting in a period of silence. Therefore, there is such a possibility that a user is anxious whether or not operation of apparatuses are normal, or whether or not reception of signals is normal. In addition, there is a possibility that a user may mistakenly assume that there is no programming on the present channel. Even when there is no such misunderstanding, this waiting time may cause discomfort or annoyance to users.
Further, this waiting time is wasted time for users and could be compounded if, for example, the broadcast content finally output after the lapse of the waiting time is not interesting to the user. In such a case, the user must change over the channels again, and must spend the waiting time again. Sometimes, a scanning operation for searching a required channel is manually or automatically carried out by successively changing channels. In such an operation, a waiting time is generated whenever a channel is changed. Therefore, annoyance to the user is intensified.
The waiting time described above is longer in a digital broadcast for mobile stations than that in a digital broadcast for stationary receiving stations, as will be described later. In a digital broadcast, an interleave is generally adopted to cope with burst error generation. In the interleave, a data array is appropriately rearranged in a transmitter side, and is returned to the original array in a receiver side. Thus, errors in the data can be dispersed, and concentrated error generation in the data can be prevented.
When the interleave is adopted, a receiver side cannot output the received signal until the data necessary for returning the data array are collected. In a digital broadcast for mobile stations, rearranging of the data in a wide range is carried out taking into consideration multipass fading and signal interruption due to large obstructions. Therefore, it takes a relatively long time to collect the data necessary for rearranging the data array. As a result, the waiting time becomes longer, and amounts to, for example, several seconds. Because the waiting time is longer in a broadcast for mobile stations, problems due to the waiting time described above are even more pronounced in a broadcast received by a moving body.
The present invention addresses the problems described above, and its object is to provide a digital broadcast receiver and a method for receiving a digital broadcast and outputting the content of the broadcast without problems, such as user discomfort caused by the waiting time until a start of output of the received signal, described above.
A digital broadcast receiver according to the present invention is characterized in that the receiver comprises waiting time signal outputting means for outputting a predetermined signal during a waiting time from the selection of a receiving channel until the output of the received signal on the selected receiving channel.
This digital broadcast receiver of the present invention can allow the user to recognize that the receiver is normally working by outputting a predetermined signal during the waiting time, and that the selected channel is on the air, and the broadcast has not stopped. In addition, the first digital broadcast receiver can reduce user discomfort due to no output. Though digital broadcasts are applicable to a broadcast for sound or a broadcast for image and sound, the present invention is not limited to such broadcasts, and are applicable to any digital broadcast.
In this digital broadcast receiver according to the present invention, the selection of the receiving channel described above may be determined so as to be the selection by the switching-on of a power source. If such a method is adopted, the predetermined signal can be output during the waiting time caused by the switching-on of a power source. As a result, it is possible for a user to recognize that the receiver is normally working, when a power source switch is switched on.
In addition, in this digital broadcast receiver according to the present invention, the predetermined signal may be an intermittent sound signal in which the interval of the intermittence varies according to the elapse of time, or an intermittent signal in which the interval of the intermittence is shortened as the time elapses. With either of these methods, a user can recognize the elapse of time, and can also be reassured that the end of the waiting time is approaching.
A second aspect of the digital broadcast receiver according to the present invention is characterized in that this receiver comprises selecting means for selecting one of a plurality of channels, a first channel receiving unit for receiving the selected channel, signal outputting means for outputting the received signal on the received channel, second channel receiving means for receiving channels which include at least one of unselected channels other than the channels selected by said selecting means, signal storage means for storing the signal received by the second channel receiving means, and waiting time output control means for controlling the signal outputting means so that the received signal stored in said signal storage means is output from said signal outputting means until the preparation for outputting the received signal in the unselected channels from said signal outputting means has been completed, when said selecting means has selected other channels different from said selected channels.
In the digital broadcast receiver according to a second aspect of the present invention, the first channel receiving unit receives the channel selected by the selecting means from a plurality of channels, and the signal outputting means outputs the received signal on the received channel. The second channel receiving means receives channels which include at least one of unselected channels other than the channels selected by the selecting means, and the signal storage means stores the received signal of the channel received by the second channel receiving means. When other channel has been selected by the selecting means, the waiting time output control means controls the signal outputting means so that the received signal stored in the signal storage means is output from the signal outputting means until the preparation for outputting the received signal of this other channel from the signal outputting means has been completed. In other words, the received signal stored in the signal storage means is output during the waiting time produced after the selection of other channel. By this method, a user can recognize that the receiver is properly working. In addition, the user can recognize that the other channel selected is on the air, and the broadcast is not stopped. Furthermore, user discomfort or annoyance as a result of no output can be reduced. In addition, although digital broadcasts are applicable to a broadcast for sound or a broadcast for image and sound, the present invention is not limited to such broadcasts, but is applicable to any digital broadcasts of any content.
In such a digital broadcast receiver according to the present invention, it is possible to configure the receiver such that the second channel receiving means successively receives at least a channel other than the channels selected by the selecting means, and the waiting time output control means controls the signal outputting means so that the received signal corresponding to the channels other than the channels selected by the selecting means among the received signals stored in the signal storage means is output. In this manner, a received signal of a channel other than the selected channel can be output during the waiting time. The received signal output during the waiting time is an old signal before the changing-over of channels, but this old signal can sufficiently inform the user of a content of the selected channel. As a result, the user can recognize the content of the selected channel without wasting the waiting time and, further, can re-select other channels if the selected channel is not a desired channel.
In addition, in the digital broadcast receiver according to the present invention, it is possible to configure the receiver such that the second channel receiving means receives the channel of a predetermined genre from a plurality of the channels. In such an aspect of the present invention, it is possible to configure the receiver such that the predetermined genre is a genre related to the channel selected before the newly selected channel. It is possible to output the received signal of the channel of the genre related to the selected channel.
Furthermore, in the digital broadcast receiver according to the present invention, it is possible to configure the receiver such that the second channel receiving means successively receives a plurality of channels, and the signal storage means stores the received signals successively received by the second channel receiving means for each channel, wherein a predetermined manipulation time control means is provided for controlling the signal outputting means so that when the predetermined manipulation has been carried out, the received signals stored in the signal storage means for each channel are successively output from the signal outputting means. In this manner, it is possible to successively output the contents of the broadcast of a plurality of channels by carrying out a predetermined manipulation. Therefore, the user can judge which channel to select according to the successively broadcast output.
A third aspect of the digital broadcast receiver according to the present invention is characterized in that the receiver comprises channel selecting means for selecting one of a plurality of channels; a receiving unit for receiving the selected channel; signal outputting means for outputting a received signal of the received channel; information storage means for storing information about said plurality of the channels; and waiting time output control means for controlling the signal outputting means so that when said selecting means have selected another channel, the information about the other channel among the information stored in said information storage means is output from the signal outputting means during a period from the selection of the other channel until the completion of the preparation for outputting the received signals of the other channel from said signal outputting means.
In the digital broadcast receiver according to the present invention, the receiving unit may receive the channel selected with the channel selecting means out of a plurality of channels, and the signal outputting means may output the received signal of the received channel. When another channel is selected with the channel selecting means, the waiting time output control means control the signal outputting means so that the information about the other channel among the information about a plurality of the channels stored in the information storage means is output from the signal outputting means during a period from the selection of the other channel until the completion of the preparation for outputting the received signal of the other channel. In other words, during a waiting time produced immediately after the selection of the other channel, the information about the other channel selected is output. In this manner, a user can recognize that the receiver is properly working, and in addition, can obtain information about the other channel selected. Of course, the user can recognize also that the other channel selected is on the air, and the broadcast of this channel is not stopped. Furthermore, user discomfort when there is no output can be softened. In addition, though the digital broadcasts are applicable to a broadcast for sound or a broadcast for image and sound, the present invention is not limited to such broadcasts, but is applicable to any digital broadcasts. The information about channels includes names of broadcast stations, broadcast programs, genres of broadcast programs, or the like.
A method for receiving and outputting a digital broadcast according to another aspect of the present invention is characterized in that, when a receiving channel has been selected, a predetermined signal is output during a waiting time from the selection of the receiving channel until the output of the receiving signal of the selected receiving channel.
With this method for receiving and outputting a digital broadcast according to the present invention, it is possible for a user to recognize that the receiver is properly working through the predetermined signal output during the waiting time. In addition, it is possible for the user to recognize that the selected channel is on the air, and the broadcast of this channel has not stopped. Further, user discomfort stemming from no output can be softened.
A method for receiving and outputting a digital broadcast according to another aspect of the present invention is characterized in that (a) received signals of a plurality of channels are successively received and stored for each channel, and (b) when a receiving channel has been selected, the received signal of the channel corresponding to the selected receiving channel is output out of said stored receiving signals during a period from the selection of the receiving channel until the completion of the preparation for outputting the received signal of the selected receiving channel.
With this method for receiving and outputting a digital broadcast according to the present invention, it is possible for a user to recognize that the receiver is properly working by outputting the stored received signal during the waiting time. In addition, it is possible to inform the user of the contents of the broadcast of the selected channel at the time just before the selection. It is possible for the user to recognize that the other channel selected is on the air, and the broadcast is not stopped. Furthermore,user discomfort stemming from no output can be reduced.
A method for receiving and outputting a digital broadcast according to still another aspect of the present invention is characterized in that (a) information about a plurality of channels is stored for each channel, and (b) when a receiving channel has been selected, information about the channel corresponding to the selected receiving channel is output out of the stored information during a period from the selection of the selected receiving channel until the completion of the preparation for outputting the received signal on the selected receiving channel.
According to this method for receiving and outputting a digital broadcast according to the present invention, it is possible for a user to recognize that the receiver is properly working by outputting information about the other channel selected during the waiting time generated immediately after selecting another channel. In addition, it is possible to inform the user of information about the other channel selected. Of course, it is possible to make the user recognize that the other channel selected is on the air, and the broadcast is not stopped. Furthermore, user discomfort or annoyance due to a lack of output can be softened.